There are many rating for anime Pg, g etc etc
*PG or G is for kids and even normal people can watch it
*PG-13 is for teenagers above 13 years old, it might contain may some **** scenes or bad words.
*R is for 18+ age people, it may contain revealing clothing or sexual scenes or blood etc
*R+ this is also 18+ but it may contain upper pars of female body like their ******* etc, and even contain gore , violence, se× scenes,
*Rx most people don't know about this
But this is just hentai, and this website also has some hentai , like overflow uncensored version is available hear and animes like kite , etc etc.

Many new people don't know about it.